There must be something I'm missing

It’s the views. You are staring into a solid marble wall.

10D sold for $2.5 million July 2012, did a major renovation, and just closed again for $2.6 million.

50% down is a lot, especially for a building which has neither prewar charm nor modern amenities.

maybe there is a stupid neighbor affecting both 10d and 10b.

is there washer/dryer in the unit?

$2.5 million ask for a 2br/2ba white brick, high equity %, mid-century UES co-op seems well above-market to me.

Market rate for one is about $1.5 million and carries a $3,000/mo maintenance charge.

So you're saving $1,000/mo per month on maintenance (thanks to the retail / garage ownership), plus $500/mo in the parking space (market value), plus $200/mo market value for utilities. That's $1,700/mo in lower monthly charges, or $20.4k per year.

Capitalize that $20.4k/year at 5% gives you a value of $408k [$20.4/5%], so the apartment SHOULD have a fundamental value of $1.9 million per year on an apples-to-apples basis [$1.5 million + $408k]

Seems like proximity to Central Park is the only swing factor for arguing the ask is close to reasonable.

Accepting the remainder of that math, I don't see the "market rate" for a decent sized UES doorman 2 bdrm/2 bath to be $1.5MM, although the core market for a place like this is hurt pretty bad by 50% financing cap. As 30yr points out, 10D sold at $2.6MM with perhaps a slightly newer and nicer renovation, but a much better view, which seems to me to ballpark this unit in low 2s. But 10D also was on the market for over 1.5 years, and 17A almost 2 years, and 8A for almost a year. So it would seem there is more to this building, although one could say these units were stubbornly overpriced to start.

I missed this: This unit was in contract in April but was re-listed in June. So, something happened. Difficult board? By the way, parking in this building is $1,000 per month (it's very expensive in this area). So with free utilities, you're almost living with no maintenance....and no flip tax.